A signal amplifier may be designed to provide a specified amount of gain or a specified range of gains. Furthermore, there may be a specified permissible amount of gain variation for a signal amplifier. In general, the gain variation present in a signal amplifier may be due to manufacturing process variations, differences in operating temperature, and so forth. Therefore, to help ensure that a signal amplifier provides an expected amount of gain, tracking and compensation circuits may be used. Typically, the tracking and compensation circuits may be analog in nature. Additionally, each signal amplifier may require dedicated tracking and compensation circuits.
The analog tracking and compensation circuits may typically be designed alongside the signal amplifier and may be fabricated on the same substrate as the signal amplifier. Therefore, the performance of the analog tracking and compensation circuits may be only as good as the accuracy of device models of the manufacturing process. Should the device models later prove to be inaccurate, the analog tracking and compensation circuits may not perform well and may need to be redesigned.
Furthermore, since each signal amplifier in a circuit may need its own analog tracking and compensation circuit, circuits with a large number of signal amplifiers or circuits fabricated with limited substrate area may have to dedicate a significant amount of substrate area to the analog tracking and compensation circuits. Additionally, the analog tracking and compensation circuits may consume a considerable amount of power, which may pose a problem in low-power applications, such as portable electronic devices.